Conventionally, there has been proposed an information output method for reading a bar code printed on a material such as a printed matter, and then, reading out and outputting information such as a voice corresponding to this bar code from a memory. For example, there has been proposed a method for storing in advance information coincident with key information imparted to storing means, making a search from a key read by means of the bar code reader, and then, outputting information or the like. In addition, there has also been proposed a technique of generating a dot pattern in which fine dot patterns are arranged in accordance with a predetermined rule so that various voice information can be outputted; picking up the dot pattern printed on a material such as a printed matter as image data by means of a camera; digitizing the picked up data; and then, outputting voice information.